(see movmies)

Vision-Based 3D Reconstruction of the Cell Cytoskeleton By  Yuan Cheng and C.F.Dewey, Jr.

Three-dimensional structure of the cell cytoskeleton has been of considerable interest in the biomedical research. Three-dimensional relationships of actin filaments provide a solid basis to interpret and model the actin-filament networks. Considerable effort has gone into defining the structural and biochemical properties of the 3-D polymer systems that comprise the cytoskeleton. One technique that has been widely applied to understanding this architecture is electron microscopy. In theory, micrographs can provide information on the length, geometry, and interaction and location of various cytoskeletal components. This architectural information is necessary to model the mechanical properties of resting and active cells. However, structural studies are often hampered by the inability to faithfully reconstruct the complex 3-D geometric relationships made by actin filaments as they course throughout the cytoplasmic space. This research attempts to develop such reconstruction technique. A vision- based reconstruction approach has been proposed and improvements of such technique is in its process.

In the vision-based reconstruction, the 3D information of objects is considered embedded in the form of disparities between neighboring images, which are extracted by finding the corresponding points in neighboring images. As an extension to the reconstruction from two images, this approach recovers 3D structure from arbitrarily n-images taken at different angles. The 3D reconstruction is first performed on each pair of neighboring images. A scoring system is introduced to evaluate the uncertainty of the reconstruction on a point-by-point basis. Such score indicates the probability of whether a point in 3D belongs to the object studied. Finally, an integration procedure is performed to combine these individual reconstructions together. A statistical model is built to determine the optimal 3D structure from the integration. A priori knowledge about the object structure is incorporated into the optimization to resolve the ambiguities and guide the process towards the correct reconstruction.

Experiments on the 3D reconstruction of the actin cytoskeleton demonstrate the feasibility of the proposed approach, which potentially will offer us an exciting way to explore medical and biological structures in a three-dimensional manner.

	Stereo Reconstruction Paper: Y.Cheng, C.Hartemink, J.Hartwig, C.F.Dewey, Three Dimensional Reconstruction of the Actin Cytoskeleton from Stereo Images, Journal of Biomechanics, 33(1), 104-114.
	......download manuscript:  .pdf or  .ps
	Demos...